The Center's Surgery Unit provides personnel with specialized skills and dedicated facilities for the conduct of major survival surgery supporting Center research programs in an environment that promotes continued health and well-being of research animals. Proposed activities will concentrate on refinement of existing techniques and development of new techniques and special devices that will better meet the needs of research programs utilizing nonhuman primates (NHPs). Key elements of the Center's centralized service for the conduct of survival surgery include the availability of professionally trained personnel, specialized facilities, and specialized equipment. With completion of the Surgery and surgery support facilities in the newly constructed Animal Services Building, the Center's surgical facilities are state-of-the-art and meet standards and guidelines of regulatory and accrediting agencies. Approximately 4,800 procedures were performed in the past 6-year-interval in support of over 90 investigators in more than 100 projects. It is anticipated that the number of investigators utilizing the Surgery Unit will increase significantly in the near future. The gene therapy program currently being developed in the Division's Infectious diseases program will require substantial surgical services, as will proposed staff additions in the Division of Reproductive Sciences. It is also expected that some of the anticipated increase in the Oregon Health Sciences University collaborative research programs focused on NHPs will require surgical services. Acquisition of critical equipment items is proposed to replace 20 + -year- old units and make available monitoring and laparoscopic equipment that is not currently available and considered the minimum essential equipment necessary to adequately provide real-time assessment of the physiologic status of animals.